Pawel Althamer (b. 1967) originally trained as a sculptor, but his work also bears the marks of relational art -- social, collaborative, participatory art that is concerned less with producing objects than with composing human interactions. Often dematerialized to the point of invisibility, this work also increasingly enlists human participants, often in what the artist describes as 'reality directed'. For Motion Pictures (2000) Althamer choreographed actors to perform everyday actions in a public square (greeting a friend, feeding pigeons) at the same time every day for three weeks. Viewers, if they didn't know what to look for, could not know whether they had seen the artwork at all. Another major element of Althamer's work is institutional critique. For a 2003 exhibition at his Berlin gallery, Neugerrieumschneider, he transformed the high-design space into a litter-strewn shell, essentially returning the gallery to its dilapidated pre-gentrification state.